The invention relates to an illumination device for illuminating a display device. In a preferred embodiment, non-polarized light from a non-polarized light source is polarized by a holographic polarization beam splitting device and focused onto a liquid crystal display device by a holographic...http://www.google.de/patents/US5784181?utm_source=gb-gplus-sharePatent US5784181 - Illumination device for illuminating a display device
